High positive rate after consecutive negative tests of SARS-CoV-2

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a global public health event since 2019. Real-time reverse transcription polymerase chain reaction (RT-PCR) assays of upper respiratory tract specimens were used as the most common method for confirmation of SARS-CoV-2. Patients diagnosed with coronavirus disease 2019 and hospitalized in Cancer Center of Wuhan Union Hospital were retrospectively enrolled. Epidemiological, clinical, and laboratory records were analyzed with highlights on the pattern of results of repeated RT-PCR tests. Nine hundred eighty-four patients admitted to hospital between February 13, 2020 to March 10, 2020 were enrolled. The median age was 62.0 years (interquartile range 49.0-68.0) and 44.5% was male. Three thousand-three hundred eleven specimens were collected for RT-PCR tests with a median of 3 tests (interquartile range 2.0-4.0) per patient. Three hundred sixty-two (36.8%) patients showed positive records from repeated RT-PCR tests. For the 362 confirmed patients, 147 cases received further RT-PCR tests after 2 consecutive negative records of SARS-CoV-2 and 38 (26%) of them obtained a positive result. Ten (23%) of 43 patients showed positive results after 3 consecutive negative tests and 4 (24%) of 17 patients were positive after 4 negative tests. Consecutive negative RT-PCR tests with respiratory specimens could not guarantee a viral clearance.